Recursion \Re*cur"sion\ (-sh?n), n. [L. recursio. See Recur.]
   The act of recurring; return. [Obs.] --Boyle.
   [1913 Webster]

	

	recursion
     n : (mathematics) an expression such that each term is generated
         by repeating a particular mathematical operation

	

	recursion n. See recursion. See also tail recursion.

	

	recursion
     
         When a function (or procedure)
        calls itself.  Such a function is called "recursive".  If the
        call is via one or more other functions then this group of
        functions are called "mutually recursive".
     
        If a function will always call itself, however it is called,
        then it will never terminate.  Usually however, it first
        performs some test on its arguments to check for a "base case"
        - a condition under which it can return a value without
        calling itself.
     
        The canonical example of a recursive function is
        factorial:
     
        	factorial 0 = 1
        	factorial n = n * factorial (n-1)
     
        Functional programming languages rely heavily on recursion,
        using it where a procedural language would use iteration.
     
        See also recursion, recursive definition, tail recursion.
     
        [Jargon File]
     
        (1996-05-11)